Confronted with the rumor Mr. Gross gave only an indirect response: “The behavior of US interest rates has defied economic logic” he said. “Usually, I put on a trade, publicize it on CNBC and markets follow. This time round it looks like we need to broaden our audience.”

Former Federal Reserve Chairman Alan Greenspan agreed: “It’s a conundrum”, he tweeted, when asked to comment on the path of interest rates.

“Every time interest rates go up, some foreign factor intervenes to push them down again,” she observed at a recent town hall meeting. “First it was the Greeks. Then the Irish. Then the Arabs. Now the Japanese!”

“It's obvious,” she continued. “This is a global conspiracy to plunge America deeper into debt. And President Obama is biting the bait. I mean, I’m not necessarily blaming him but the Kobe earthquake also happened under a Democrat President… It's an interesting coincidence…”

Meanwhile, Federal Reserve Chairman Ben Bernanke played down the threat of excessive market volatility due to millions of “sell” tweets.

“The Fed stands ready to use all available tools to preserve financial stability,” he tweeted.

Fed pundits have interpreted the Chairman’s tweet as a sign he is bracing for what they called the "nuclear" option.

In response, Mr Bernanke regretted the term as "inopportune", saying the media must learn to settle with less sensational jargon, "like QE3". He added that recent experience has shown QE to be "a monetary policy tool 4 all seasons", though he did not elaborate, likely due to tweet constraints.

Fed insiders say Mr. Bernanke still struggles with Twitter and has enlisted pop star Lady Gaga to help him master the new medium. Reportedly, her top recommendations have been to reduce FOMC statements to 140 characters or less and to change the Chairman’s profile name from @Ben to @MoneyHoney.